The Justice Department is considering whether to ask the U.S. Supreme Court to dismiss a lawsuit alleging that a former attorney general, John Ashcroft, set up detention policies that opened the way for the abuse of Muslims who were arrested and held at Brooklyn’s federal jail after the September 11, 2001, terrorist attacks.

In a 2003 report, the Justice Department concluded that some correctional officers at the Brooklyn facility engaged in “a pattern of physical and verbal abuse against some September 11 detainees” that included slamming inmates into walls. No policymakers in Washington, D.C., have been implicated.

Several Muslim men who were detained in Brooklyn in 2001 and part of 2002 are trying to hold Mr. Ashcroft and the director of the FBI, Robert Mueller, responsible for the beatings and threats they endured while being held on minor charges as the FBI investigated if they were connected to the hijackings.

Last year, a federal appeals court in Manhattan allowed the first of the suits to go forward against Messrs. Ashcroft and Mueller. The plaintiff is a former detainee, Javaid Iqbal, who now sells cellular phones in his native Pakistan after being deported there. He claims Messrs. Ashcroft and Mueller approved of keeping him and others under restrictive conditions, including solitary confinement, communications blackouts, and four-officer escorts for each inmate.

In a recent court filing, Justice Department lawyers hinted they would try to get the Supreme Court to stop Iqbal’s suit from proceeding.

“The Solicitor General for the United States is currently considering whether to authorize a petition” to the Supreme Court on behalf of Messrs. Ashcroft and Mueller, a Justice Department lawyer, Stephen Handler, wrote last month.

At the same time, the Justice Department provided the first explanation for how Iqbal came to the attention of the FBI after the September 11 attacks. Before his arrest, Iqbal had lived on Long Island for a decade and worked as a convenience store clerk, gas station attendant, and cable technician, the New York Times reported.

A recently disclosed January 2002 report from the FBI investigation into the terrorist attacks says a former employer of Iqbal told the FBI of hearing a “friend and co-worker of Iqbal’s” say that “Iqbal might have been involved and wanted for a bombing in Pakistan.”

“It was unfounded,” a lawyer for Iqbal, Elizabeth Koob, said in a brief interview. “He was cleared of any terrorist activity and deported.”

It is unclear what steps the FBI ultimately took to follow up on the tip.

“We don’t have any evidence that was ever followed up on, or ever taken seriously,” another lawyer for Iqbal, Alexander Reinert, said. In a brief, Mr. Handler, the government attorney, claims that this tip provided the basis for the FBI to classify him as “of interest” to the investigation into the September 11 attacks. That classification led to Iqbal being held under restrictive conditions usually reserved for suspects charged with killings. At the time, the government was holding Iqbal on identification fraud charges, to which Iqbal pleaded guilty.